Electronics Design

This week the goal is to redraw the Echo hello board using any circuit design software and add atleast an LED and a push button to it. The Echo hello board is shown below.


The software I am using to redraw the circuit is Eagle by Autodesk. It is a freeware and is available for download from autodesk homepage.

After installing the software I went through some online tutorial videos that help me understand the placing and connecting of various components. It was also necesaary to load the Fab Library to the software so that one could add the components that are available in the lab.
For this the Fab library is provided by the Fab Academy. Copy the text into a new text file and rename as "fab.lbr". Now copy this file in the lbr folder of Eagle software.

Since an LED was to br added to the ciruit , the current through it has to be balanced. For this a resistance is to be used. To calculate the value of the resistance use the formula V=IR (Ohm's law). I used a 499ohm resistor for my LED.

The components used are

Designing the PCB

For Designing, open Eagle. Then create a New Project and select Schematic Go to Libraby and select Fab library. All the components available in the lab will be showcased in that library.
Browse all the components from the library and add them one by one. Place is in a way that connecting the components become easy.

Connect all the componets according to the schematic



Add a switch and LED to the circuit.

After all the components are connected, recheck for errors and proceed towards Route generation.


Set the design rules according to the tolerances of the machine



Arrange the components at suitable distances and select auto routing

Look for 100% efficiency and select the design.




When the route is generated select another layer to draw the route for cutting the PCB

Export both trace and cut files as different png files into a folder. These are to be saved as monochrome so that Fab module can read it.

Error

After PCB milling there was an error I noticed in the circuit design before soldering

Why the error occured

There is a tool in Eagle for checking the errors in the schematic and also the board design. I had run the error check but I unknowingly missed the part where the software mentioned the error in the design. I accidently skipped the error and proceeded with the design. I later run the error report again to check the actual problem with the schematic. Below is the screenshot of the error.

How I fixed it

The circuit was later removed using paper cutter

Final Board

The original design files can be downloaded from below

  • Cut file
  • Trace
  • Board
  • Schematic